Our patent-pending double-wall vacuum insulation means that the temperature outside a Hydro Flask has a very hard time affecting the temperature of whatever you might put in it. The best part is that this is a two-way street; whether you’ve got hot or chilled liquids inside of your Hydro Flask, the internal temperature won’t affect the temperature of the container in your hand. That means no blistered fingers with your daily cup of Joe, and no troublesome sweat rings—from your bottle of ice water. Hydro Flasks are pretty amazing, but we can’t make guarantees about individual personal hygiene practices!
18/8 stainless steel is the preferred material wherever food or beverages are concerned because it does not affect flavor, either by adding any metallic taste of its own, or by retaining any flavor from the previous foodstuffs with which it came into contact. This is a function of the combination of chromium and nickel, which creates a non-porous surface that inhibits the growth of bacteria. Bacteria, which are the cause of odors, like to cling to porous surfaces where they can thrive. At the first sign of soapy water, any bacteria that have dried onto the surface of 18/8 stainless steel are swept cleanly away.
FEATURES:

We are so convinced that Hydro Flasks are the best vacuum-sealed insulated bottles available that we guarantee every Hydro Flask against manufacturer’s defects for 100 years or one lifetime, whichever comes first!
There's no warranty card to fill out or receipt to keep. You don’t even have to worry about taking your Hydro Flask back to the store where you purchased it. Please note that if it is just your cap that is not working correctly, you do not need to send in any products. Hydro Flask is not responsible for lost or misdirected packages. If the problem lies in the insulation, please follow the instructions below.

Simply contact us and tell us what the problem is. Our Customer Care Department will provide you with the necessary information to get you the replacement bottle or cap you need. When shipping your Hydro Flask, we encourage you to use a traceable method (such as UPS or insured mail) and ship in a sturdy, cardboard box.
Once your Hydro Flask is received by us, it will be inspected by our Warranty Department. If we determine that your warranty claim is the result of a manufacturer’s defect, we will replace your Hydro Flask and ship a new one back to you free of charge. If we determine that your warranty claim is NOT the result of a manufacturer’s defect, you will be responsible for paying to have your Hydro Flask shipped back to you.
If your Hydro Flask qualifies under warranty, it will be replaced by the same size and color. If the same color and size is no longer available, it will be replaced by one of similar size and color and will not be of lesser MSRP value. Requested substitutions will not be honored.
This warranty extends only to you, the original purchaser of the Hydro Flask, and lasts for 100 years or one lifetime, whichever comes first. This warranty covers all parts of the Hydro Flask and applies to defects or failure during standard use, except for: loss-theft, dishwasher use or normal wear and tear (dents, scratches etc).
When sending your Hydro Flask, please include your name, address, telephone number, email address, and a brief note explaining what’s wrong. Please address shipment to:
Hydro Flask Attn: Warranty 900 SE Wilson Ave. Ste. H Bend, OR 97702
Once we receive your shipment, please allow 2-3 weeks for return delivery. You will receive an email from us informing you once your Hydro Flask has shipped. Shipping is free for warranty items in the United States. For all other countries the replacement item will be free, but you will be responsible for shipping charges.
If you have any questions, please e-mail to us at info@hydroflask.com or call us at 888-58-HYDRO ext 1.
Hydro Flask is dedicated to making our customers happy and will do everything we can to help!

Before Initial Use:

Wash with hot, soapy water and a small amount of baking soda (the baking soda is not absolutely necessary, but is helpful).

Put the lid on and shake

Rinse

Fill and drink

After Every Use:

Wash with warm water and soap (and baking soda, if needed).

Rinse

Air dry with the lid off

Fill, drink and enjoy

Why should I buy a stainless steel Hydro Flask?
Your favorite beverages will taste just the same pouring out as they did going in. Additionally, they will maintain their hot or cold qualities for 12-24 hours. Hydro Flask bottles also have no linings or coatings, and are 100% BPA-free. Whether the contents are hot coffee or ice-cold water, flavors won’t linger, and the bottle’s materials won’t leach into your drink.
Last but certainly not least, for every Hydro Flask sold, we will donate 5% to a charity you choose. Following a purchase, simply go to FivePercentBack.org, choose from the list of available causes, enter your bottle’s serial number and that’s it: Your 5% goes to work.

Can my new Hydro Flask hold juice?
Yes. Juice, water, alcohol, ice, warm beverages, cold beverages – any and all will taste great out of your stainless steel Hydro Flask bottle. Our bottles are made from food-grade 18/8 stainless steel. As long as you care for your bottle by washing and rinsing it after use, what comes out will taste just as it did going in.

Can I put my Hydro Flask bottle in the freezer?
No, we do not recommend putting your Hydro Flask bottle in the freezer. For maximum temperature efficiency, we recommend pre-cooling, and pre-warming. Simply place cold (even ice) water or warm water in the bottles, replace the lid, and let stand for five to ten minutes before replacing with your beverage of choice. Hydro Flasks are all but impervious to the outside elements, therefore the freezer won't really have an effect on them.

Can I put my Hydro Flask bottle in the microwave?
Never. Your Hydro Flask is not meant to go in the microwave. In general, we highly recommend using caution when drinking hot beverages directly from any of our products. Too hot of liquids can scald the user. Also, keep out of reach of small children when product contains warm to hot liquids.

Are your vacuum insulated bottles dishwasher safe?
We do not recommend putting your Hydro Flask bottles in the dishwasher. Our products are printed with extremely tough ink. However, we opted for an eco-friendly ink over one that may withstand the dishwasher better. That being said, even if the logo and coating come off, the bottle is still 100% safe.
Ultimately, however, we suggest hand washing your Hydro Flask as there are other issues with the vacuum that can play a factor as well. Therefore, if your Hydro Flask goes through the dishwasher it instantly voids the warranty.

How can I maximize how long my Hydro Flask keeps its temperature?
We recommend pre-chilling or pre-heating the inner layer prior to use. For cold liquids, fill it with ice cold water, put the lid on, shake it up, empty and then add your liquid, topping it off with a few extra ice cubes for good measure. Similarly, for hot liquids, fill with hot tap water, screw on lid, let stand for 3-5 min, then dump out the water and replace it with your favorite winter warmer.

Is Hydro Flask a thermos?
We try not to step on toes on this one, but we will say that we Do Not use glass as the insulator. Wikipedia has this to say: "A vacuum flask, colloquially called a thermos after a ubiquitous brand, is a storage vessel which provides thermal insulation by interposing a partial vacuum between the contents and the ambient environment. The evacuated region of the partial vacuum removes material that could serve as a heat conductor or carrier, enabling the flask to keep its contents hotter or cooler than its surroundings. Vacuum flasks are commonly used as insulated shipping containers.
The vacuum flask was invented by Scottish physicist and chemist Sir James Dewar in 1892 and is sometimes referred to as a Dewar flask after its inventor. The first vacuum flasks for commercial use were made in 1904 when a German company, Thermos GmbH, was formed. Thermos, their trademark for their flasks, remains a registered trademark in some countries but was declared a genericized trademark in the U.S. in 1963 as it is colloquially synonymous with vacuum flasks in general".

I fly a non-pressurized plane. Will my Hydro Flask have issues with the vacuum at altitude?
Not at all. And they are not a problem to check on commercial planes, either. Why wait for the flight attendant to pour you two sips when you can be set for the duration of your flight?

What is stainless steel and what kind does Hydro Flask use?
Stainless steel is defined as a steel alloy with a minimum 10% chromium content by mass. There are different grades and surface finishes of stainless steel, some better suited for a particular environment than others. Stainless steel is 100% recyclable. In fact, according to the International Stainless Steel Forum, an average stainless steel object is composed of about 60% recycled material -25% originating from end-of-life products and 35% coming from manufacturing processes. Hydro Flask uses premium type-304 food-grade stainless steel, also known as “classic 18/8 stainless steel.” And referred to as “A” in compliance with ISO 3506 Food Grade Stainless Steel.

Where are Hydro Flasks made?
Hydro Flasks, along with nearly all stainless steel sports bottles, are made in China.
Even before the very first Hydro Flask was ever produced, a tremendous amount of time, energy, and yes even a bit of blood, sweet, and tears went into creating the absolute best Stainless Steel bottle on the planet.
Many of our questions and concerns were the same as yours. We believe that to be an active participant in the world today requires more than a mere passing interest in the social and economical topics that we are all currently facing.
After all of the frequent flyer miles were used, the suitcases were unpacked, and the dust had settled, we found that we really are best off (at least for now) having our bottles hand crafted in China.
After numerous visits, reports, emails, pictures, and phone calls we realized that China is NOT one big sweat shop that the US media would like us to believe. They do some things that are not quite up to America’s “standards” and we are by no means trying to understate that. We are, however, trying to help spread the word that there are many reputable business in China that practice many of the same work standards that we enjoy here in the US.
At Hydro Flask we require each of the factories that we work with to operate ethically, fairly, and to treat all of their employees with the utmost respect and dignity that they deserve. To that end, our management team makes regular quality assurance visits to our factories in Asia. We continually monitor that our high standards are achieved. Even though we’re proud of all the work we’ve accomplished so far, we know our standards program is, by no means, perfect. Therefore, we are constantly looking for opportunities to improve and grow our fair labor program to influence both change and knowledge.
While factory assessments remain the focal point of our fair treatment program, they are only part of a multifaceted approach that addresses the root causes of any noncompliance issues at the factories and business with which we work. Great consideration is spent on the core issues within the larger context of our industry.
At Hydro Flask we work hard to make sure you receive only the highest quality stainless steel products that are built with the fairness, care, and dignity that can only come from someone proud to be a member of our extended family.